This Bare Knuckle Pickups 550K pot has been custom made for them by industry leaders CTS who are renowned for their high quality potentiometers.

The 550 K Ohms resistance gives a brighter tone than 250 K and is traditionally used for humbucking pickups and it has a logarithmic audio taper which BKP use for both volume and tone controls with their humbucker and P90 pickups. They spec 550 K over the standard 500K pots to open out the upper frequency range and allow the full harmonic richness of their pickups to shine through, improving detail and clarity. The pots have a 10% tolerance for higher accuracy and an imperial 3/8" threaded shaft with fine 24 spline mounting for control knobs (commonly found on guitars made in the USA like Gibson, Fender or PRS Core). To use metric knobs that have a set screw (smooth interior, no splines) simply line up the set screw with the split in the shaft and tighten the screw.